2 * Author: Tatu Ylonen <ylo@cs.hut.fi>
3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
6 * As far as I am concerned, the code I have written for this software
7 * can be used freely for any purpose. Any derived versions of this
8 * software must be clearly marked as such, and if the derived work is
9 * incompatible with the protocol description in the RFC file, it must be
10 * called by a name other than "ssh" or "Secure Shell".
13 * Copyright (c) 1999, 2000, 2001 Markus Friedl. All rights reserved.
15 * Redistribution and use in source and binary forms, with or without
16 * modification, are permitted provided that the following conditions
18 * 1. Redistributions of source code must retain the above copyright
19 * notice, this list of conditions and the following disclaimer.
20 * 2. Redistributions in binary form must reproduce the above copyright
21 * notice, this list of conditions and the following disclaimer in the
22 * documentation and/or other materials provided with the distribution.
24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
25 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
26 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
27 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
28 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
29 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
30 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
31 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
32 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
33 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35 /* RCSID("$OpenBSD: channels.h,v 1.40 2001/06/25 08:25:36 markus Exp $"); */
42 /* Definitions for channel types. */
43 #define SSH_CHANNEL_X11_LISTENER 1 /* Listening for inet X11 conn. */
44 #define SSH_CHANNEL_PORT_LISTENER 2 /* Listening on a port. */
45 #define SSH_CHANNEL_OPENING 3 /* waiting for confirmation */
46 #define SSH_CHANNEL_OPEN 4 /* normal open two-way channel */
47 #define SSH_CHANNEL_CLOSED 5 /* waiting for close confirmation */
48 #define SSH_CHANNEL_AUTH_SOCKET 6 /* authentication socket */
49 #define SSH_CHANNEL_X11_OPEN 7 /* reading first X11 packet */
50 #define SSH_CHANNEL_INPUT_DRAINING 8 /* sending remaining data to conn */
51 #define SSH_CHANNEL_OUTPUT_DRAINING 9 /* sending remaining data to app */
52 #define SSH_CHANNEL_LARVAL 10 /* larval session */
53 #define SSH_CHANNEL_RPORT_LISTENER 11 /* Listening to a R-style port */
54 #define SSH_CHANNEL_CONNECTING 12
55 #define SSH_CHANNEL_DYNAMIC 13
56 #define SSH_CHANNEL_ZOMBIE 14 /* Almost dead. */
57 #define SSH_CHANNEL_MAX_TYPE 15
59 #define SSH_CHANNEL_PATH_LEN 30
62 * Data structure for channel data. This is initialized in channel_new
63 * and cleared in channel_free.
66 typedef struct Channel Channel;
68 typedef void channel_callback_fn(int id, void *arg);
69 typedef int channel_filter_fn(struct Channel *c, char *buf, int len);
72 int type; /* channel type/state */
73 int self; /* my own channel identifier */
74 int remote_id; /* channel identifier for remote peer */
75 /* peer can be reached over encrypted connection, via packet-sent */
76 int istate; /* input from channel (state of receive half) */
77 int ostate; /* output to channel (state of transmit half) */
78 int flags; /* close sent/rcvd */
79 int rfd; /* read fd */
80 int wfd; /* write fd */
81 int efd; /* extended fd */
82 int sock; /* sock fd */
83 int isatty; /* rfd is a tty */
84 Buffer input; /* data read from socket, to be sent over
85 * encrypted connection */
86 Buffer output; /* data received over encrypted connection for
89 char path[SSH_CHANNEL_PATH_LEN];
90 /* path for unix domain sockets, or host name for forwards */
91 int listening_port; /* port being listened for forwards */
92 int host_port; /* remote port to connect for forwards */
93 char *remote_name; /* remote hostname */
103 char *ctype; /* type */
106 channel_callback_fn *cb_fn;
109 channel_callback_fn *dettach_user;
112 channel_filter_fn *input_filter;
115 #define CHAN_EXTENDED_IGNORE 0
116 #define CHAN_EXTENDED_READ 1
117 #define CHAN_EXTENDED_WRITE 2
119 /* default window/packet sizes for tcp/x11-fwd-channel */
120 #define CHAN_SES_WINDOW_DEFAULT (32*1024)
121 #define CHAN_SES_PACKET_DEFAULT (CHAN_SES_WINDOW_DEFAULT/2)
122 #define CHAN_TCP_WINDOW_DEFAULT (32*1024)
123 #define CHAN_TCP_PACKET_DEFAULT (CHAN_TCP_WINDOW_DEFAULT/2)
124 #define CHAN_X11_WINDOW_DEFAULT (4*1024)
125 #define CHAN_X11_PACKET_DEFAULT (CHAN_X11_WINDOW_DEFAULT/2)
127 /* possible input states */
128 #define CHAN_INPUT_OPEN 0x01
129 #define CHAN_INPUT_WAIT_DRAIN 0x02
130 #define CHAN_INPUT_WAIT_OCLOSE 0x04
131 #define CHAN_INPUT_CLOSED 0x08
133 /* possible output states */
134 #define CHAN_OUTPUT_OPEN 0x10
135 #define CHAN_OUTPUT_WAIT_DRAIN 0x20
136 #define CHAN_OUTPUT_WAIT_IEOF 0x40
137 #define CHAN_OUTPUT_CLOSED 0x80
139 #define CHAN_CLOSE_SENT 0x01
140 #define CHAN_CLOSE_RCVD 0x02
143 /* channel management */
145 Channel *channel_lookup(int id);
147 channel_new(char *ctype, int type, int rfd, int wfd, int efd,
148 int window, int maxpack, int extusage, char *remote_name, int nonblock);
150 channel_set_fds(int id, int rfd, int wfd, int efd,
151 int extusage, int nonblock);
152 void channel_free(Channel *c);
153 void channel_free_all(void);
155 void channel_send_open(int id);
156 void channel_request(int id, char *service, int wantconfirm);
157 void channel_request_start(int id, char *service, int wantconfirm);
158 void channel_register_callback(int id, int mtype, channel_callback_fn *fn, void *arg);
159 void channel_register_cleanup(int id, channel_callback_fn *fn);
160 void channel_register_filter(int id, channel_filter_fn *fn);
161 void channel_cancel_cleanup(int id);
163 /* protocol handler */
165 void channel_input_channel_request(int type, int plen, void *ctxt);
166 void channel_input_close(int type, int plen, void *ctxt);
167 void channel_input_close_confirmation(int type, int plen, void *ctxt);
168 void channel_input_data(int type, int plen, void *ctxt);
169 void channel_input_extended_data(int type, int plen, void *ctxt);
170 void channel_input_ieof(int type, int plen, void *ctxt);
171 void channel_input_oclose(int type, int plen, void *ctxt);
172 void channel_input_open_confirmation(int type, int plen, void *ctxt);
173 void channel_input_open_failure(int type, int plen, void *ctxt);
174 void channel_input_port_open(int type, int plen, void *ctxt);
175 void channel_input_window_adjust(int type, int plen, void *ctxt);
177 /* file descriptor handling (read/write) */
180 channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
182 void channel_after_select(fd_set * readset, fd_set * writeset);
183 void channel_output_poll(void);
185 int channel_not_very_much_buffered_data(void);
186 void channel_close_all(void);
187 void channel_free_all(void);
188 int channel_still_open(void);
189 char *channel_open_message(void);
190 int channel_find_open(void);
192 /* channel_tcpfwd.c */
194 channel_request_local_forwarding(u_short listen_port,
195 const char *host_to_connect, u_short port_to_connect, int gateway_ports);
197 channel_request_forwarding(const char *listen_address, u_short listen_port,
198 const char *host_to_connect, u_short port_to_connect, int gateway_ports,
201 channel_request_remote_forwarding(u_short port, const char *host,
202 u_short remote_port);
203 void channel_permit_all_opens(void);
204 void channel_add_permitted_opens(char *host, int port);
205 void channel_clear_permitted_opens(void);
206 void channel_input_port_forward_request(int is_root, int gateway_ports);
207 int channel_connect_to(const char *host, u_short host_port);
208 int channel_connect_by_listen_adress(u_short listen_port);
212 int x11_connect_display(void);
213 char *x11_create_display(int screen);
214 char *x11_create_display_inet(int screen, int x11_display_offset);
215 void x11_input_open(int type, int plen, void *ctxt);
216 void x11_request_forwarding(void);
218 x11_request_forwarding_with_spoofing(int client_session_id,
219 const char *proto, const char *data);
220 void deny_input_open(int type, int plen, void *ctxt);
222 /* agent forwarding */
224 void auth_request_forwarding(void);
225 char *auth_get_socket_name(void);
226 void auth_sock_cleanup_proc(void *pw);
227 int auth_input_request_forwarding(struct passwd * pw);
228 void auth_input_open_request(int type, int plen, void *ctxt);
232 typedef void chan_event_fn(Channel * c);
234 /* for the input state */
235 extern chan_event_fn *chan_rcvd_oclose;
236 extern chan_event_fn *chan_read_failed;
237 extern chan_event_fn *chan_ibuf_empty;
239 /* for the output state */
240 extern chan_event_fn *chan_rcvd_ieof;
241 extern chan_event_fn *chan_write_failed;
242 extern chan_event_fn *chan_obuf_empty;
244 int chan_is_dead(Channel * c);
245 void chan_mark_dead(Channel * c);
246 void chan_init_iostates(Channel * c);
247 void chan_init(void);